This book seems to be bringing something new and interesting every chapter! In this chapter I really thought that by injecting a correct amount of Vitamin A into an embryo and let that embryo develop, it will form a duplicate image. This can lead to potential super humans. "Mad" scientists can take this Vitamin A serum and inject it into a baby fetus and let it develop two brains, since two "heads" are better than one! Not only may the future hold double brain power but the inject able serum can create humans with multiple arms or multiple legs. The "humans" can posses abilities that no human can. While this subject has a bright or creepy future one thing is for sure, it has a sister or brother topic in chemistry. In chemistry (and maybe physics), scientist can create doubles or a whole new thing by taking an atom and blasting it with energy that is either protons or electrons and turn that atom into something else. They may even be able to split an atom and still keep its properties and try to make it stable.